Molecular Playground/Human Protective Protein Cathepsin A

One of the CBI Molecules being studied in the University of Massachusetts Amherst Chemistry-Biology Interface Program at UMass Amherst and on display at the Molecular Playground.

Human Lysosomal Protective Protein Cathepsin A (PPCA)


The human protective protein cathepsin A forms a multi-enzyme complex with beta-galactosidase and neuraminidase in lysosomes. PPCA has so far two functions:a catalytic activity overlapping with that of Cathepsin A and a protective function towards lysosomal beta-galactosidase and neuraminidase. The stability and activity of the latter glycosidases depend on their interaction with PPCA [1].



PPCA Glycosylation sites
PPCA, is synthesized as a 542 amino acid precursor with a molecular weight of 54kDa. and it dimerizes soon after synthesis. The sequence contains two glycosylation sites, Asn 117 and Asn 305. It also contains nine cysteines. The spinning protein (PPCA Glycosylation sites ) is human protective protein with the glycosylation sites represented in stick model colored by atom.

Additional Resources
For additional information, see: Metabolic Disorders

References:
[1] Jackman, H. L., Morris, P. W., Deddish, P. A., Skidgel, R. A. and Erdos, E. G. (1992) J. Biol. Chem. 267, 2872-2875

Molecular Playground banner: Lysosomal Human Protective Protein Cathepsin A, a lysosomal chaperone, Nobody chaperones the chaperone. That's why it is so right for this job.